The hazard class of a hazardous material is indicated either by its class (or division) number, its class name, or by the letters ``ORM-D''. The following table lists class numbers, division numbers, class or division names and those sections of this subchapter which contain definitions for classifying hazardous materials, including forbidden materials. ------------------------------------------------------------------------
49 CFR
Division reference
Class No. No. (if Name of class or division for
any) definitions------------------------------------------------------------------------None ........... Forbidden materials.......... 173.21None ........... Forbidden explosives......... 173.541 1.1 Explosives (with a mass 173.50
explosion hazard).1 1.2 Explosives (with a projection 173.50
hazard).1 1.3 Explosives (with 173.50
predominately a fire hazard).1 1.4 Explosives (with no 173.50
significant blast hazard).1 1.5 Very insensitive explosives; 173.50
blasting agents.1 1.6 Extremely insensitive 173.50
detonating substances.2 2.1 Flammable gas................ 173.1152 2.2 Non-flammable compressed gas. 173.1152 2.3 Poisonous gas................ 173.115
3 ........... Flammable and combustible 173.120
liquid.4 4.1 Flammable solid.............. 173.1244 4.2 Spontaneously combustible 173.124
material.4 4.3 Dangerous when wet material.. 173.1245 5.1 Oxidizer..................... 173.1275 5.2 Organic peroxide............. 173.1286 6.1 Poisonous materials.......... 173.1326 6.2 Infectious substance 173.134
(Etiologic agent).7 ........... Radioactive material......... 173.4038 ........... Corrosive material........... 173.1369 ........... Miscellaneous hazardous 173.140
material.None ........... Other regulated material: ORM- 173.144
D.------------------------------------------------------------------------ [Amdt. 173-224, 55 FR 52606, Dec. 21, 1990, as amended at 57 FR 45460, Oct. 1, 1992; Amdt. 173-234, 58 FR 51531, Oct. 1, 1993] Sec. 173.2a Classification of a material having more than one hazard.
(a) Classification of a material having more than one hazard. Except as provided in paragraph (c) of this section, a material not specifically listed in the Sec. 172.101 table that meets the definition of more than one hazard class or division as defined in this part, shall be classed according to the highest applicable hazard class of the following hazard classes, which are listed in descending order of hazard:
(1) Class 7 (radioactive materials, other than limited quantities; and shipments of UN 3507, Uranium hexafluoride, radioactive material, excepted package)
(2) Division 2.3 (poisonous gases).
(3) Division 2.1 (flammable gases).
(4) Division 2.2 (nonflammable gases).
(5) Division 6.1 (poisonous liquids), Packing Group I, poisonous-by-inhalation only.
(6) A material that meets the definition of a pyrophoric material in Sec. 173.124(b)(1) of this subchapter (Division 4.2).
(7) A material that meets the definition of a self-reactive material in Sec. 173.124(a)(2) of this subchapter (Division 4.1).
(8) Class 3 (flammable liquids), Class 8 (corrosive materials), Division 4.1 (flammable solids), Division 4.2 (spontaneously combustible materials), Division 4.3 (dangerous when wet materials), Division 5.1 (oxidizers) or Division 6.1 (poisonous liquids or solids other than Packing Group I, poisonous-by-inhalation). The hazard class and packing group for a material meeting more than one of these hazards shall be determined using the precedence table in paragraph (b) of this section.
(9) Combustible liquids.
(10) Class 9 (miscellaneous hazardous materials).
(b) Precedence of hazard table for Classes 3 and 8 and Divisions 4.1, 4.2, 4.3, 5.1 and 6.1. The following table ranks those materials that meet the definition of Classes 3 and 8 and Divisions 4.1, 4.2, 4.3, 5.1 and 6.1:
Precedence of Hazard Table
[ Hazard class or division and packing group ]--------------------------------------------------------------------------------------------------------------------------------------------------------
5.1 5.1 5.1 6.1, 8,
4.2 4.3 I II III 6.1, I I 6.1 6.1 8, I 8, I 8, II 8, II 8, III III
\1\ \1\ \1\ dermal oral II III liquid solid liquid solid liquid solid--------------------------------------------------------------------------------------------------------------------------------------------------------3 I\2\.................................................. ... 4.3 ... ... ... 3 3 3 3 3 (\3\) 3 (\3\) 3 (\3\)3 II\2\................................................. ... 4.3 ... ... ... 3 3 3 3 8 (\3\) 3 (\3\) 3 (\3\)3 III\2\................................................ ... 4.3 ... ... ... 6.1 6.1 6.1 3\4\ 8 (\3\) 8 (\3\) 3 (\3\)4.1 II \2\.............................................. 4.2 4.3 5.1 4.1 4.1 6.1 6.1 4.1 4.1 (\3\) 8 (\3\) 4.1 (\3\) 4.14.1 III \2\............................................. 4.2 4.3 5.1 4.1 4.1 6.1 6.1 6.1 4.1 (\3\) 8 (\3\) 8 (\3\) 4.14.2 II.................................................. ... 4.3 5.1 4.2 4.2 6.1 6.1 4.2 4.2 8 8 4.2 4.2 4.2 4.24.2 III................................................. ... 4.3 5.1 5.1 4.2 6.1 6.1 6.1 4.2 8 8 8 8 4.2 4.24.3 I................................................... ... ... 5.1 4.3 4.3 6.1 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.34.3 II.................................................. ... ... 5.1 4.3 4.3 6.1 4.3 4.3 4.3 8 8 4.3 4.3 4.3 4.34.3 III................................................. ... ... 5.1 5.1 4.3 6.1 6.1 6.1 4.3 8 8 8 8 4.3 4.3
5.1 I \1\............................................... ... ... ... ... ... 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.15.1 II \1\.............................................. ... ... ... ... ... 6.1 5.1 5.1 5.1 8 8 5.1 5.1 5.1 5.15.1 III \1\............................................. ... ... ... ... ... 6.1 6.1 6.1 5.1 8 8 8 8 5.1 5.16.1 I, Dermal........................................... ... ... ... ... ... ....... .... ... .... 8 6.1 6.1 6.1 6.1 6.16.1 I, Oral............................................. ... ... ... ... ... ....... .... ... .... 8 6.1 6.1 6.1 6.1 6.16.1 II, Inhalation...................................... ... ... ... ... ... ....... .... ... .... 8 6.1 6.1 6.1 6.1 6.16.1 II, Dermal.......................................... ... ... ... ... ... ....... .... ... .... 8 6.1 8 6.1 6.1 6.16.1 II, Oral............................................ ... ... ... ... ... ....... .... ... .... 8 8 8 6.1 6.1 6.16.1 III................................................. ... ... ... ... ... ....... .... ... .... 8 8 8 8 8 8--------------------------------------------------------------------------------------------------------------------------------------------------------\1\ See Sec. 173.127.\2\ Materials of Division 4.1 other than self-reactive substances and solid desensitized explosives, and materials of Class 3 other than liquid
desensitized explosives.\3\ Denotes an impossible combination.\4\ For pesticides only, where a material has the hazards of Class 3, Packing Group III, and Division 6.1, Packing Group III, the primary hazard is
Division 6.1, Packing Group III.
Note 1: The most stringent packing group assigned to a hazard of the material takes precedence over other packing groups; for example, a material meeting Class 3 PG II and Division 6.1 PG I (oral toxicity) is classified as Class 3 PG I.
Note 2: A material which meets the definition of Class 8 and has an inhalation toxicity by dusts and mists which meets criteria for Packing Group I specified in Sec. 173.133(a)(1) must be classed as Division 6.1 if the oral or dermal toxicity meets criteria for Packing Group I or II. If the oral or dermal toxicity meets criteria for Packing Group III or less, the material must be classed as Class 8.
(c) The following materials are not subject to the provisions of paragraph (a) of this section because of their unique properties:
(1) A Class 1 (explosive) material that meets any other hazard class or division as defined in this part shall be assigned a division in Class 1. Class 1 materials shall be classed and approved in accordance with Sec. 173.56 of this part;
(2) A Division 5.2 (organic peroxide) material that meets the definition of any other hazard class or division as defined in this part, shall be classed as Division 5.2;
(3) A Division 6.2 (infectious substance) material that also meets the definition of another hazard class or division, other than Class 7, or that also is a limited quantity Class 7 material, shall be classed as Division 6.2;
(4) A material that meets the definition of a wetted explosive in Sec. 173.124(a)(1) of this subchapter (Division 4.1). Wetted explosives are either specifically listed in the Sec. 172.101 table or are approved by the Associate Administrator (see Sec. 173.124(a)(1) of this subchapter); and
(5) A limited quantity of a Class 7 (radioactive) material that meets the definition for more than one hazard class or division shall be classed in accordance with Sec. 173.423. [Amdt. 173-224, 55 FR 52606, Dec. 21, 1990, as amended at 56 FR 66264, Dec. 20, 1991; Amdt. 173-241, 59 FR 67490, Dec. 29, 1994; Amdt. 173-247, 60 FR 48787, Sept. 20, 1995; Amdt. 173-244, 60 FR 50307, Sept. 28, 1995; 64 FR 10776, Mar. 5, 1999; 66 FR 33426, June 21, 2001; 66 FR 45182, 45379, Aug. 28, 2001; 68 FR 45032, July 31, 2003; 80 FR 1151, Jan. 8, 2015]